Lens apparatus and image pickup apparatus including the same

Abstract

To provide a lens device which is compact while having a wide angle of view.SOLUTION: A lens apparatus according to one embodiment of the present invention includes an optical system consisting of, in order from an object side to an image side, a first lens unit having a negative refractive power and a rear unit having a positive refractive power, wherein in the optical system, an interval between adjacent lens units is changed during zooming, and the rear unit includes at least one lens unit and an aperture stop, wherein a focus group including one or a plurality of lens groups among the lens groups included in the rear group moves in a direction of an optical axis during focusing, and satisfies a conditional expression of ωw>85 when a half angle of view at the time of focusing on infinity at a wide angle end is ωw (°), the lens apparatus including a holding member configured to hold the focus group, and a drive member configured to move the holding member in a direction of the optical axis, the drive member and the aperture stop overlapping each other in a direction orthogonal to the optical axis.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lens device and an imaging device having the same, and is suitable for imaging devices using solid-state imaging elements such as digital still cameras, video cameras, broadcast cameras, surveillance cameras, and vehicle-mounted cameras, or imaging devices such as cameras using silver halide photographic film. [Background technology]

[0002] Lens devices used in imaging devices are required to have good optical characteristics while providing a wide angle of view. A known wide-angle lens device is a negative-lead lens device, as disclosed in Patent Document 1, in which a lens group having negative refractive power is positioned closest to the object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-166234 Summary of the Invention [Problem to be solved by the invention]

[0004] In a wide-angle lens device, the entire lens device tends to be large, so in order to reduce the size of the wide-angle lens device, it is necessary to appropriately arrange the components that make up the focus mechanism. [Means for solving the problem]

[0005] One aspect of the present invention provides a lens device comprising an optical system consisting of a first lens group having negative refractive power and a rear group having positive refractive power, arranged in that order from the object side to the image side, wherein the spacing between adjacent lens groups in the optical system changes during zooming, the rear group includes one or more lens groups and an aperture stop, a focus group consisting of one or more lens groups included in the rear group moves in the optical axis direction during focusing, and the lens device satisfies the condition ωw>85, where ωw (°) is the half angle of view when focusing at infinity at the wide-angle end, and the lens device comprises a holding member that holds the focus group and a driving member that moves the holding member in the optical axis direction, and wherein the driving member and the aperture stop overlap in a direction perpendicular to the optical axis. [Effects of the Invention]

[0006] It is possible to provide a lens device that has a wide angle of view and is compact. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view of a lens device according to a first embodiment of the present invention; [Figure 2] Aberration diagram of the lens device of Example 1 [Figure 3] 10 is a cross-sectional view of a lens device according to a second embodiment of the present invention; [Figure 4] Aberration diagram of the lens device of Example 2 [Figure 5] 10 is a cross-sectional view of a lens device according to a third embodiment of the present invention; [Figure 6] Aberration diagram of the lens device of Example 3 [Figure 7] 10 is a cross-sectional view of a lens device according to a fourth embodiment of the present invention; [Figure 8] Aberration diagram of the lens device of Example 4 [Figure 9] 10 is a cross-sectional view of a lens device according to a fifth embodiment of the present invention; [Figure 10] Aberration diagram of the lens device of Example 5 [Figure 11] 10 is a cross-sectional view of a lens device according to a sixth embodiment of the present invention; [Figure 12] Aberration diagram of the lens device of Example 6 [Figure 13] Schematic diagram of the imaging device [Figure 14] Cross-sectional views showing lens barrels of the respective embodiments. [Figure 15] Diagram showing the shape of the rear fixed barrel into which the filter barrel is installed [Figure 16] 10 is a cross-sectional view showing the arrangement of members around a driving member in a comparative example. [Figure 17] 1 is a cross-sectional view showing the reduction in size in the optical axis direction due to the arrangement around the driving member in this embodiment. [Figure 18] 1 is a cross-sectional view showing the reduction in size in the optical axis direction and the radial direction due to the arrangement around the driving member in this embodiment. [Figure 19] 1 is a cross-sectional view showing the radial size reduction achieved by the arrangement around the driving member in this embodiment. [Figure 20] A cross-sectional view showing the miniaturization in the optical axis direction due to the arrangement of the driving member and the control board in this embodiment. [Figure 21] Cross-sectional view showing the layout of the aperture stop, focus barrel, control board, and filter barrel DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the drawings. Note that the drawings may be drawn at a scale different from the actual scale for convenience. In addition, the same reference numerals are used for the same components in the drawings, and duplicated descriptions will be omitted.

[0009] 1, 3, 5, 7, 9, and 11 are cross-sectional views of the lens apparatus L0 of Examples 1 to 6 at the wide-angle end when focused on infinity. The lens apparatus L0 of each Example is used in imaging devices such as digital video cameras, digital still cameras, broadcast cameras, silver halide film cameras, and surveillance cameras, as well as optical equipment including interchangeable lenses. In each cross-sectional view, the left side is the object side, and the right side is the image side.

[0010] The lens device L0 in each embodiment is composed of multiple lens groups. Note that a lens group in this specification refers to a group of one or more lenses that move together during zooming. In the lens device L0 in each embodiment, the spacing between adjacent lens groups changes during zooming from the wide-angle end to the telephoto end.

[0011] In each cross-sectional view, Li denotes the i-th (i is a natural number) lens group included in the lens device L0, counting from the object side, and LR denotes the rear group, which includes all lenses and lens groups arranged closer to the image side than the first lens group L1.

[0012] In each cross-sectional view, SP denotes an aperture stop. In each cross-sectional view, IP denotes an image plane, and when the lens apparatus L0 of each embodiment is used as the photographic optical system of a digital still camera or digital video camera, the imaging surface of a solid-state image sensor such as a CCD sensor or a photoelectric conversion element such as a CMOS sensor is disposed thereon. Furthermore, when the lens apparatus L0 of each embodiment is used as the photographic optical system of a silver halide film camera, a photosensitive surface corresponding to the film surface is disposed at the image plane IP.

[0013] The solid arrows in each lens cross-sectional diagram represent, in a simplified form, the movement locus of each lens group during zooming from the wide-angle end to the telephoto end. In this specification, the wide-angle end and the telephoto end refer to the respective zoom positions when each lens group is located at the opposite ends of the range of movement along the optical axis. The dashed arrows in each lens cross-sectional diagram represent, in a simplified form, the movement locus of the focus group LF as it moves relative to the image plane during focusing from infinity to a close distance.

[0014] The lens device L0 in each embodiment includes, in order from the object side to the image side, a first lens group L1 having negative refractive power and a rear group LR including one or more lens groups. The rear group LR includes all lens groups arranged closer to the image side than the first lens group L1. Note that in the lens device L0 in each embodiment, an optical element with substantially no refractive power, such as a low-pass filter or an infrared cut filter, may be arranged between the lens arranged closest to the image side and the imaging plane.

[0015] 2, 4, 6, 8, 10, and 12 are aberration diagrams of the lens device L0 of Examples 1 to 6. Each aberration diagram shows the aberration of each Example when focused at infinity, with (A) at the wide-angle end, (B) at the intermediate zoom position, and (C) at the telephoto end.

[0016] In the spherical aberration diagrams, Fno is the F-number, and the solid line indicates the amount of spherical aberration for the d-line (wavelength 587.6 nm) and the two-dot dashed line indicates the amount of spherical aberration for the g-line (wavelength 435.8 nm). In the astigmatism diagrams, ΔS indicates the amount of astigmatism on the sagittal image plane, and ΔM indicates the amount of astigmatism on the meridional image plane. In the distortion diagrams, the solid line indicates the amount of distortion for the d-line. In the chromatic aberration diagrams, the two-dot dashed line indicates the amount of chromatic aberration at the g-line. Also, in each aberration diagram, ω is the imaging half angle of view (°), which is the angle of view calculated by paraxial calculation.

[0017] In the lens device L0 of each embodiment, the projection method of Examples 1 to 3 employs the conformal projection method, which is expressed by the formula Y=f·θ. Furthermore, the projection method of Examples 4 to 6 employs the equisolid angle projection method, which is expressed by the formula Y=2·f·sin(θ / 2), where f represents the focal length of the entire system of the lens device L0, and θ represents the angle of incidence of the light ray. Note that in the lens devices of each embodiment, the projection method is not limited to the conformal projection method or the equisolid angle projection method, and other projection methods may also be used.

[0018] FIG. 14 is a cross-sectional view showing a lens barrel according to this embodiment. The line XX in the figure represents the optical axis. In FIG. 14, a mount 101 is a component fixed to a camera body (not shown). A guide barrel 102 is fixed integrally to the mount 101 together with a rear fixed barrel 131 and an intermediate fixed barrel 132. A cam ring 104 is held on the outer periphery of the guide barrel 102 so as to be rotatable around the optical axis. The cam ring 104 is connected to a zoom ring 105, which is held on the outer periphery of the intermediate fixed barrel 132 so as to be rotatable, by a key member (not shown), and is configured to rotate integrally with the zoom ring 105 by operating the zoom ring 105 from the outside.

[0019] The zoom sensor 106 is attached to the intermediate fixed barrel 132 and is a sensor that can electrically detect the rotation angle of the zoom ring 105. The zoom sensor 106 is electrically connected to a control board 107 and transmits focal length information during zooming to a control circuit.

[0020] The control board 107 is electrically connected to a contact block 108, and performs communication with the camera body (not shown) and power supply.

[0021] The first lens group L1 is held by a first group barrel 111, and the first group barrel 111 is in contact with a guide barrel .

[0022] The second lens group L2 is held by a second group barrel 112 and abuts against a second group base barrel 119.

[0023] The third lens group L3 is held by a third group barrel 113 and abuts against a rear group base barrel 120.

[0024] The fourth lens group L4 is held by a fourth group barrel 114 and abuts against a rear group base barrel 120.

[0025] The rear group base barrel 120 is a cylindrical member in the focus mechanism, holds an aperture stop 121 , and is electrically connected to the control board 107 .

[0026] The fifth lens group L5 is held in a fifth-group barrel 115, and the fifth-group barrel 115 is held by a guide bar (not shown) so as to be movable relative to the rear-group base barrel 120 in the optical axis direction.

[0027] In one example of this embodiment, the fifth lens group L5 is a lens for focus adjustment, and is driven in the optical axis direction via a rack 123 by a driving member 122 connected to a lead screw held in the rear group base barrel 120. In other words, the rack 123 is a transmission member that transmits the driving force of the driving member 122 to a holding member, which will be described later. The driving member 122 is electrically connected to the control board 107 by a flexible printed circuit board (not shown). The driving member 122 is a member having a mechanism capable of driving the holding member, such as a stepping motor connected to a lead screw, an ultrasonic motor, or a voice coil motor.

[0028] The second-group barrel 119 and the rear-group base barrel 120 are each barrels that move during zooming, and cam followers (not shown) are fixed to the second-group barrel 119 and the rear-group base barrel 120. Each cam follower is engaged with a linear groove provided in the guide barrel 102 and a cam groove provided in the cam ring 104, and is configured so that by rotating the cam ring 104, each can move linearly in the optical axis direction.

[0029] Furthermore, the fifth-group barrel 115, which is a holding member for holding the focus group LF for focus adjustment, is fixed to the rear-group base barrel 120, and is driven in the optical axis direction by a driving member 122 while moving together with the rear-group base barrel 120 during zooming.

[0030] The filter 110 is held by a filter barrel 117 and is incorporated between the sixth-group barrel 116 and the mount 101. As shown in FIG. 15 , an opening H is provided in the rear fixed barrel 131, allowing the filter barrel 117 to be incorporated. The filter 110 corresponds to an optical member such as a drop-in filter. The filter barrel 117 corresponds to a filter holding member.

[0031] Next, the characteristic configuration of the lens device L0 of each embodiment will be described.

[0032] The lens device L0 in each embodiment is a negative-lead type lens device in which the first lens group L1 has negative refractive power. Of the lenses included in the first lens group L1, the lens G1 closest to the object is preferably fixed relative to the image plane during zooming. This prevents the overall optical length of the lens device L0 from changing during zooming, thereby improving the robustness of the lens device L0.

[0033] When the half angle of view of the lens device L0 at the wide-angle end when focused at infinity is ωw (°), satisfying the condition ωw>85 will enable the wide angle of view required for a fisheye lens device or an ultra-wide-angle lens device. Furthermore, to obtain a sufficiently wide angle of view for a fisheye lens device or an ultra-wide-angle lens device, it is more preferable to satisfy the condition ωw>92. Furthermore, it is even more preferable to satisfy the condition ωw>94.

[0034] In addition, in the lens device L0 of each embodiment, the members that make up the focus mechanism are appropriately arranged.

[0035] Figure 16 is a comparative example showing the layout around the drive member 122. Consider a configuration in which the drive member 122 and the five-group barrel 115, which is a holding member for focus adjustment, are arranged on the image side of the aperture stop 121, as in this embodiment. The drive member 122 requires at least space in the optical axis direction to ensure a stroke during focusing for the motor unit and rack 123. If the drive member 122 is arranged on the image side of the aperture stop 121 as in Figure 16, a large amount of space must be secured in the optical axis direction on the image side of the aperture stop 121, which results in an increase in the size of the lens barrel.

[0036] FIG. 17 is a diagram illustrating the layout of the driving member 122 and its surroundings in this embodiment. As shown in FIG. 17, the various components are arranged so that the driving member 122 overlaps with the aperture stop 121 in a direction perpendicular to the optical axis. This configuration ensures sufficient space for the driving member 122, while shortening the overall length of the lens barrel in the optical axis direction, thereby enabling the lens device L0 to be made more compact. In this disclosure, the phrase "the driving member 122 and the aperture stop 121 overlap in a direction perpendicular to the optical axis" means that at least a portion of the aperture stop 121 is hidden by the driving member 122 when the driving member 122 and the aperture stop 121 are viewed from a direction perpendicular to the optical axis. The driving member 122 and the aperture stop may or may not be in contact with each other.

[0037] With the above configuration, a lens device that has a wide angle of view yet is small in size can be obtained.

[0038] Next, conditions that the lens device L0 of each embodiment should preferably satisfy will be described.

[0039] It is preferable that the lens device L0 of each embodiment satisfies at least one of the following conditional expressions (1) to (12): In each conditional expression, the various numerical values ​​are expressed as follows:

[0040] The focal length of the first lens group L1 is fL1, and the focal length of the second lens group L2 is fL2.

[0041] The focal length of the lens device L0 at the wide-angle end is defined as fw.

[0042] The focal length of the lens G1 arranged closest to the object in the first lens group L1 is defined as fG1, and the focal length of the lens G2 arranged adjacent to the lens G1 on the image side is defined as fG2.

[0043] The focal length of the focus group LF is defined as fLF.

[0044] The focal length of the rear lens unit LR at the wide-angle end of the lens device L0 is set to fLRw.

[0045] The back focus of the lens device L0 at the wide-angle end is Skw.

[0046] The distance on the optical axis from the aperture stop SP of the lens device L0 at the wide-angle end to the lens surface closest to the image side is denoted as DSPw.

[0047] The refractive index of the material of the lens G1 closest to the object in the first lens group L1 with respect to the d-line is set to ndG1.

[0048] Of the lens surfaces of the lens G1 closest to the object side in the first lens group L1, the radius of curvature of the object-side lens surface is R1, and the radius of curvature of the image-side lens surface is R2.

[0049] The maximum image height that can be photographed at the telephoto end of the lens device L0 is Yta, and the maximum image height that can be photographed at the wide-angle end is Ywa.

[0050] -3.0 <fL1 / fw<-1.7 (1) -5.0<|fL2| / fL1<-1.1 (2) 1.4 <fG1 / fL1<3.0 (3) 0.40 <fG1 / fG2<1.60 (4) 3.5 <fLF / fw<15.0 (5) -4.1 <fLF / fL1<-1.8 (6) -1.30 <fL1 / fLRw<-0.55 (7) 2.0 <Skw / fw<6.0 (8) 0.40 <DSPw / Skw<1.00 (9) 1.65 <ndG1<2.20 (10) 1.3<(R1+R2) / (R1-R2)<3.0 (11) 1.5 <Yta / Ywa<3.0 (12)

[0051] Here, the technical meaning of the above-mentioned conditional expressions (1) to (12) will be explained.

[0052] Conditional expression (1) defines the ratio of the focal length fL1 of the first lens group L1 to the focal length fw of the lens device L0 at the wide-angle end. By satisfying conditional expression (1), the focal length fL1 of the first lens group L1 can be appropriately determined, thereby enabling favorable correction of distortion, lateral chromatic aberration, and field curvature. If the focal length fL1 of the first lens group L1 becomes too long, falling below the lower limit of conditional expression (1), the first lens group L1 becomes too large, making it difficult to reduce the size of the lens device L0. If the focal length fL1 of the first lens group L1 becomes too short, exceeding the upper limit of conditional expression (1), the image height change due to coma becomes large, making it difficult to correct field curvature and astigmatism.

[0053] Conditional expression (2) defines the ratio of the focal length fL2 of the second lens group L2 to the focal length fL1 of the first lens group L1. By satisfying conditional expression (2), the focal length fL1 of the first lens group L1 and the focal length fL2 of the second lens group L2 can be appropriately determined, thereby enabling favorable correction of distortion, lateral chromatic aberration, and field curvature. If the focal length fL1 of the first lens group L1 is too short, falling below the lower limit of conditional expression (2), the image height change due to off-axial coma becomes large, making it difficult to correct field curvature and astigmatism. If the focal length fL1 of the first lens group L1 is too long, exceeding the upper limit of conditional expression (2), the first lens group L1 becomes too large, making it difficult to reduce the size of the lens device L0.

[0054] Conditional expression (3) defines the ratio between the focal length fG1 of the lens G1 closest to the object in the first lens group L1 and the focal length fL1 of the first lens group L1. By satisfying conditional expression (3), the focal length fG1 of the lens G1 can be appropriately positioned, thereby enabling favorable correction of distortion, lateral chromatic aberration, and field curvature. If the focal length fG1 of the lens G1 falls below the lower limit of conditional expression (3) and becomes too short, it becomes difficult to correct field curvature and distortion. If the focal length fG1 of the lens G1 exceeds the upper limit of conditional expression (3) and becomes too long, the first lens group L1 becomes large, making it difficult to reduce the size of the lens device L0.

[0055] Conditional expression (4) defines the ratio between the focal length fG1 of the lens G1 closest to the object in the first lens group L1 and the focal length fG2 of the lens G2 arranged adjacent to the lens G1 on the image side. Two negative lenses are arranged in order from the object side to achieve a wider angle of view. If the focal length fG1 of the lens G1 becomes too short, falling below the lower limit of conditional expression (4), it becomes difficult to correct curvature of field and distortion. If the focal length fG1 of the lens G1 becomes too long, exceeding the upper limit of conditional expression (4), the lens G1 and the first lens group L1 become large, making it difficult to reduce the size of the lens device L0.

[0056] Conditional expression (5) defines the ratio of the focal length fLF of the focus group LF to the focal length fw of the lens device L0 at the wide-angle end. If the focal length fLF of the focus group LF falls below the lower limit of conditional expression (5) and becomes too short, it becomes difficult to suppress fluctuations in various aberrations, including spherical aberration, that occur during focusing. If the focal length fLF of the focus group LF exceeds the upper limit of conditional expression (5) and becomes too long, the amount of movement that occurs during focusing becomes large, making it difficult to reduce the size of the lens device L0.

[0057] Conditional expression (6) defines the ratio of the focal length fLF of the focus group LF to the focal length fL1 of the first lens group L1. If the focal length fLF of the focus group LF becomes too long by falling below the lower limit of conditional expression (6), the amount of movement required for focusing becomes long, making it difficult to reduce the size of the optical system. If the focal length fLF of the focus group LF becomes too short by exceeding the upper limit of conditional expression (6), it becomes difficult to suppress fluctuations in various aberrations, including spherical aberration, that occur during focusing.

[0058] Conditional expression (7) defines the ratio of the focal length fL1 of the first lens unit L1 to the focal length fLRw of the rear lens unit LR at the wide-angle end. If the focal length fL1 of the first lens unit L1 becomes too long, falling below the lower limit of conditional expression (7), the convergence action of the rear lens unit LR becomes large, resulting in significant lateral chromatic aberration and axial chromatic aberration, degrading optical performance. If the focal length fL1 of the first lens unit L1 becomes too short, exceeding the upper limit of conditional expression (7), it becomes difficult to correct spherical aberration and coma in the rear lens unit LR.

[0059] Conditional expression (8) defines the ratio of the back focal length Skw at the wide-angle end to the focal length fw of the lens apparatus L0 at the wide-angle end. If the back focal length Skw is too short, falling below the lower limit of conditional expression (8), it becomes difficult to place an optical element such as a low-pass filter near the image sensor that photoelectrically converts the optical image formed by the lens apparatus L0. If the back focal length Skw is too long, exceeding the upper limit of conditional expression (8), the total optical length of the lens apparatus L0 at the wide-angle end becomes long, making it difficult to achieve compact size.

[0060] Conditional expression (9) defines the ratio of the distance DSPw on the optical axis from the aperture stop SP to the lens surface closest to the image at the wide-angle end to the back focal length Skw at the wide-angle end. If the distance DSPw on the optical axis from the aperture stop SP to the lens surface closest to the image becomes too short by falling below the lower limit of conditional expression (9), it becomes difficult to arrange the focus group LF. If the back focal length Skw becomes too short by exceeding the upper limit of conditional expression (9), the total optical length of the lens apparatus L0 at the wide-angle end becomes long, making it difficult to achieve compact size.

[0061] Conditional expression (10) defines the refractive index ndG1 at the d-line of the material of the lens G1 in the first lens group L1 closest to the object. By satisfying conditional expression (10), the refractive index of the material of lens G1 can be set within an appropriate range, thereby enabling good correction of lateral chromatic aberration.

[0062] If the lower limit of conditional expression (10) is exceeded and the refractive index ndG1 of the lens G1 closest to the object becomes too small, it becomes necessary to weaken the refractive power of the negative lens in order to correct the curvature of field, which results in an increase in back focus and makes it difficult to reduce the size of the lens device L0.If the upper limit of conditional expression (10) is exceeded, the refractive index ndG1 of the lens G1 closest to the object becomes too large, which makes it necessary to select a high-dispersion material with a small Abbe number, making it difficult to effectively correct distortion and chromatic aberration of magnification.

[0063] Conditional expression (11) defines the shape of the lens G1 closest to the object in the first lens group L1. R1 is the radius of curvature of the object-side lens surface of the lens G1 closest to the object, and R2 is the radius of curvature of the image-side lens surface of the lens G1 closest to the object. If conditional expression (11) is satisfied, and the lower limit of conditional expression (11) is not satisfied, the refractive power of the lens G1 closest to the object becomes too strong, making it difficult to achieve high optical performance. If the upper limit of conditional expression (11) is exceeded, the refractive power of the lens G1 closest to the object becomes too weak, making it difficult to achieve a wide angle of view.

[0064] Conditional expression (12) defines the ratio between the maximum image height Yta that can be photographed at the telephoto end and the maximum image height Ywa that can be photographed at the wide-angle end. The maximum image height is the distance between the optical axis and an image point at which the peripheral light intensity is 15% among all image points that can be photographed. If the maximum image height at the telephoto end falls below the lower limit of conditional expression (12) and becomes too small, it becomes difficult to make the lens device L0 a wide-angle lens device that encompasses a range from a circular fisheye to a diagonal fisheye.

[0065] If the upper limit of conditional expression (12) is exceeded and the maximum image height at the telephoto end becomes too large, the amount of movement of each lens group during zooming or the refractive power of each lens group becomes large, making it difficult to suppress various aberrations during zooming.

[0066] It is preferable that the numerical ranges of the conditional expressions (1) to (12) be set to the numerical ranges of the following conditional expressions (1a) to (12a). -2.6 <fL1 / fw<-1.9 (1a) -3.6<|fL2| / fL1<-1.6 (2a) 1.6 <fG1 / fL1<2.7 (3a) 0.47 <fG1 / fG2<1.30 (4a) 4.4 <fLF / fw<10.0 (5a) -3.9 <fLF / fL1<-2.1 (6a) -1.20 <fL1 / fLRw<-0.60 (7a) 4.0 <Skw / fw<5.3 (8a) 0.50 <DSPw / Skw<0.81 (9a) 1.66 <ndG1<1.96(10a) 1.5<(R1+R2) / (R1-R2)<2.7 (11a) 1.8 <Yta / Ywa<2.3 (12a)

[0067] It is more preferable that the numerical ranges of the conditional expressions (1) to (12) are set to the numerical ranges of the following conditional expressions (1b) to (12b). -2.5 <fL1 / fw<-2.0 (1b) -3.4<|fL2| / fL1<-1.7 (2b) 1.7 <fG1 / fL1<2.6 (3b) 0.48 <fG1 / fG2<1.20 (4b) 4.6 <fLF / fw<8.0 (5b) -3.7 <fLF / fL1<-2.2 (6b) -1.10 <fL1 / fLRw<-0.63 (7b) 4.3 <Skw / fw<4.9 (8b) 0.53 <DSPw / Skw<0.79 (9b) 1.71 <ndG1<1.91 (10b) 1.7<(R1+R2) / (R1-R2)<2.5 (11b) 1.9 <Yta / Ywa<2.1 (12b)

[0068] 18, it is preferable to arrange the driving member 122 and the aperture stop 121 so that they overlap in the optical axis direction. In this arrangement, the motor section of the driving member 122 is arranged closer to the object than the aperture stop 121 and further inward than the outer diameter. The rack 123 is also arranged so that it can move on the outer diameter side of the aperture stop 121. With this arrangement, it is possible to ensure space for arranging the driving member 122, while also making the lens barrel smaller in the radial direction as well as the optical axis direction.

[0069] 19, it is preferable to arrange the rack 123 and the aperture stop 121 so that they overlap in the optical axis direction. In this arrangement, the drive member 122 is arranged further inward than in the configuration of FIG. 18, and the rack 123 is arranged so that it can move only on the image side of the aperture stop 121. With this arrangement, it is possible to ensure space for arranging the drive member 122, while further reducing the size of the lens barrel in the radial direction.

[0070] 20, it is preferable to arrange drive member 122 so that it overlaps with cutout portion N of control board 107. In this arrangement, control board 107 is made into a C-shape with a portion of the circle cut out, and drive member 122 is arranged in the space created by the cutout portion. With this arrangement, there is no need to secure space in the optical axis direction for drive member 122 and control board 107, and the lens barrel can be made smaller in the optical axis direction.

[0071] 21, it is preferable to arrange the components that make up the focusing mechanism in the following order from the object side to the image side: aperture stop 121, five-group lens barrel 115 for focus adjustment, control board 107, and filter barrel 117. Because it is not possible to arrange a lens on the image side of filter barrel 117, by arranging filter barrel 117 on the side closest to the image in the focusing mechanism, it is possible to reduce the back focus. Furthermore, by arranging control board 107 on the object side of filter barrel 117, it is not necessary to secure space in the optical axis direction for drive member 122 and control board 107, and therefore it is possible to make the lens barrel smaller in the optical axis direction.

[0072] 18 to 21, for example, the driving member 122 and the aperture diaphragm 121 overlapping in a direction perpendicular to the optical axis means that when the driving member 122 and the aperture diaphragm 121 are viewed from a direction perpendicular to the optical axis, at least a portion of the aperture diaphragm 121 is hidden by the driving member 122. The same applies when multiple members overlap in the optical axis direction. Furthermore, the driving member 122 and the aperture diaphragm may or may not abut on each other.

[0073] Next, a detailed description will be given of the configuration of the lens device L0 according to Examples 1 to 6. Note that in the lens device L0 according to each Example, a description of the overlapping configuration will be omitted, and differences from Example 1 will be mainly described.

[0074] [Example 1] FIG. 1 shows a cross-sectional view of a lens device L0 according to a first embodiment. The lens device L0 of the first embodiment comprises a first lens group L1 and a rear lens group LR. In the lens device L0 of the first embodiment, the rear lens group LR comprises a second lens group L2 with negative refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with positive refractive power, and a fifth lens group L5 with negative refractive power. During zooming from the wide-angle end to the telephoto end, the first lens group L1 remains stationary relative to the image plane, while the second lens group L2, the third lens group L3, the fourth lens group L4, and the fifth lens group L5 move toward the object side. The focus group LF is the fourth lens group L4.

[0075] In the lens device L0 of Example 1, the first lens group L1 is composed of two negative lenses. The second lens group L2 is composed of, arranged in order from the object side, one negative lens, a cemented lens consisting of a positive lens and a negative lens, and a cemented lens consisting of a negative lens and a positive lens. The third lens group L3 is composed of, arranged in order from the object side, a cemented lens consisting of two positive lenses and a negative lens, an aperture stop, and one positive lens. The fourth lens group L4 is composed of, arranged in order from the object side, a negative lens and a positive lens. The fifth lens group L5 is composed of two cemented lenses consisting of a negative lens and a positive lens. Having three cemented lenses in the optical system further improves the correction effect of axial chromatic aberration.

[0076] In the lens device L0 of the first embodiment, the focus group LF is the fourth lens group L4, and therefore the fourth group barrel 114 is a holding member for the focus group.

[0077] [Example 2] 3 shows a cross-sectional view of the lens device L0 of Example 2. In the lens device L0 of Example 2, the third lens group L3 is composed of, arranged in order from the object side, one positive lens, a cemented lens composed of a negative lens and a positive lens, an aperture stop, and one positive lens.

[0078] [Example 3] 5 shows a cross-sectional view of a lens device L0 according to a third embodiment. In the lens device L0 according to the third embodiment, the second lens group L2 is composed of, arranged in order from the object side, a cemented lens consisting of a positive lens and a negative lens, one negative lens, and a cemented lens consisting of a negative lens and a positive lens. The third lens group L3 is composed of, arranged in order from the object side, one positive lens, a cemented lens consisting of a positive lens and a negative lens, one positive lens, and an aperture stop.

[0079] [Example 4] FIG. 7 shows a cross-sectional view of a lens device L0 of Example 4. In the lens device L0 of Example 4, the second lens group L2 is composed of, in order from the object side, a positive lens, a negative lens, a negative lens, and a positive lens. The third lens group L3 is composed of, in order from the object side, a cemented lens composed of a positive lens and a negative lens, a cemented lens composed of a positive lens, a negative lens, and a positive lens, and an aperture stop. The fourth lens group L4 is composed of, in order from the object side, a positive lens and a negative lens. The fifth lens group L5 is composed of, in order from the object side, a negative lens and a positive lens.

[0080] [Example 5] FIG. 9 shows a cross-sectional view of a lens device L0 according to a fifth embodiment. The lens device L0 of the fifth embodiment comprises a first lens group L1 and a rear lens group LR. In the lens device L0 of the fifth embodiment, the rear lens group LR comprises a second lens group L2 with negative refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with positive refractive power, a fifth lens group L5 with positive refractive power, and a sixth lens group L6 with negative refractive power. During zooming from the wide-angle end to the telephoto end, the first lens group L1 remains stationary relative to the image plane, while the second lens group L2, the third lens group L3, the fourth lens group L4, the fifth lens group L5, and the sixth lens group L6 move toward the object side. The focus group LF is the fifth lens group L5.

[0081] In the lens device L0 of Example 5, the second lens group L2 is composed of, in order from the object side, a positive lens and a negative lens. The third lens group L3 is composed of a cemented lens consisting of a positive lens and a negative lens. The fourth lens group L4 is composed of, in order from the object side, two cemented lenses consisting of a negative lens and a positive lens, and an aperture stop. The fifth lens group L5 is composed of one positive lens. The sixth lens group L6 is composed of, in order from the object side, a negative lens, a positive lens, and a cemented lens consisting of a negative lens and a positive lens.

[0082] In the lens device L0 of the fifth embodiment, the focus group LF is the fifth lens group L5, and therefore the fifth group barrel 115 is a holding member for the focus group.

[0083] [Example 6] FIG. 11 shows a cross-sectional view of a lens device L0 according to a sixth embodiment. In the lens device L0 according to the sixth embodiment, the second lens group L2 is composed of a cemented lens consisting of a negative lens and a positive lens, and one negative lens. The third lens group L3 is composed of a cemented lens consisting of a positive lens and a negative lens. The fourth lens group L4 is composed of a cemented lens consisting of a positive lens, a negative lens, and a positive lens, and an aperture stop. The fifth lens group L5 is composed of a positive lens and a negative lens, arranged in that order from the object side. The sixth lens group L6 is composed of a cemented lens consisting of a positive lens, a negative lens, and a positive lens, arranged in that order from the object side. By having three cemented lenses in the optical system, the effect of correcting axial chromatic aberration can be further improved.

[0084] Next, a description will be given of the configuration that is preferably satisfied in the lens device of each embodiment.

[0085] In the lens device L0 of each embodiment, it is preferable that the first lens group L1 has two or more negative lenses in order from the object side. Also, it is preferable that the lens G1 closest to the object side has a meniscus shape convex toward the object side, and that the vertex of the object-side surface of the lens G1 closest to the object side is located closer to the object side than the first-group barrel 111. This makes it easy to achieve a wide angle of view for the lens device L0.

[0086] In the lens device L0 of each embodiment, it is preferable to make the object-side lens surface and image-side lens surface of the lens G1, which is located closest to the object, a meniscus shape with a convex surface facing the object side, because this makes it easier to manufacture the lens device L0 while satisfying the required optical performance.

[0087] In the lens device L0 of each embodiment, it is preferable that the first lens group L1 is composed of two negative lenses. Also, in the lens device L0 of each embodiment, it is preferable that all of the lenses included in the first lens group L1 are spherical lenses, because this makes it easier to manufacture the lens device L0.

[0088] In the lens apparatus L0 of each embodiment, the focus group LF is preferably composed of two or fewer lenses and is located closer to the image side than the aperture stop SP, as this facilitates the miniaturization of the focus group LF and the speed of focusing. Furthermore, the lens apparatus L0 of each embodiment employs a rear-focus type in which the focus group LF is included in the rear group LR. This prevents the overall lens length from changing during focusing, making it possible to suppress breathing caused by focusing.

[0089] In the lens device L0 of each embodiment, it is more preferable to configure the rear group LR with three or more lens groups, since this makes it possible to achieve a sufficient zoom ratio.

[0090] The lens device L0 in each embodiment may be provided with distortion correction data for correcting distortion. This allows distortion occurring in the lens optical system to be corrected by the lens device L0. In this case, the lens device L0 is provided with storage means for storing the distortion correction data.

[0091] In addition, in the lens device L0 of each embodiment, any of the arrangement methods shown in FIGS. 17 to 21 may be adopted for the arrangement around the driving member 122, or a combination of multiple arrangement methods may be used.

[0092] Next, Numerical Examples 1 to 6 corresponding to Examples 1 to 6, respectively, are shown below. In the surface data of each Numerical Example, r represents the radius of curvature of each optical surface, and d (mm) represents the distance on the optical axis between the mth surface and the (m+1)th surface. Here, m is the surface number counted from the light incident side. Furthermore, nd represents the refractive index of the material of each optical element with respect to the d-line, and vd represents the Abbe number of the material of the optical element. Note that the Abbe number vd of a certain material is given by the following equation, where Nd, NF, and NC are the refractive indices at the d-line (587.6 nm), F-line (486.1 nm), and C-line (656.3 nm) of the Fraunhofer lines: νd=(Nd-1) / (NF-NC) It is expressed as:

[0093] In each numerical example, d, focal length (mm), F-number, and half angle of view (°) are all values ​​when the lens device L0 of each example is focused on an object at infinity. The back focus is the distance on the optical axis from the lens surface of the lens device L0 closest to the image to the paraxial image plane, expressed as an air-equivalent length. The total lens length is the distance on the optical axis from the lens surface of the lens device L0 closest to the object to the lens surface closest to the image, plus the back focus. The lens group in each numerical example is not limited to being composed of multiple lenses, but may also be composed of a single lens.

[0094] Furthermore, if the optical surface is aspherical, an * symbol is added to the right of the surface number. The aspherical shape is expressed as follows, where X is the displacement from the vertex of the surface in the optical axis direction, h is the height from the optical axis in a direction perpendicular to the optical axis, R is the paraxial radius of curvature, K is the conic constant, and A4, A6, A8, A10, and A12 are the aspherical coefficients of each order. X=(h 2 / R) / [1+[1-(1+K)(h / R) 2 ] 1 / 2 ]+A4×h 4 +A6×h 6 +A8×h 8 +A10×h 10 +A12×h 12 +A14×h 14

[0095] In addition, "e±XX" in each aspherical coefficient is "×10± XX " represents.

[0096] [Numerical Example 1] Unit: mm Surface Data Surface number rd nd νd 1 48.932 2.00 1.85150 40.8 2 20.284 16.25 3 557.363 1.10 1.80400 46.5 4 28.772 (variable) 5 34.855 0.90 1.85896 22.7 6 17.068 0.10 1.53344 52.7 7* 17.589 4.70 8 50.857 6.99 1.83400 37.2 9 -20.635 1.05 1.49700 81.7 10 22.129 4.34 11 -16.265 0.80 1.49700 81.7 12 21.161 3.64 1.66565 35.6 13 -55.693 (variable) 14 21.234 3.68 1.63980 34.5 15 -27.788 0.70 1.90043 37.4 16 12.518 4.24 1.59270 35.3 17 -87.908 0.91 18 (Aperture) ∞ 2.09 19 42.390 4.09 1.49700 81.7 20 -19.741 (variable) 21 -19.756 0.90 2.00100 29.1 22 -46.915 0.10 1.53344 52.7 23* -32.818 0.25 24 49.974 5.10 1.49700 81.7 25 -15.524 (variable) 26 -39.407 0.70 1.81600 46.6 27 24.127 5.47 1.49700 81.7 28 -23.248 (variable) Image plane ∞ Aspheric data Side 7 K = 0.00000e+00 A 4= 4.48181e-07 A 6= 3.99220e-08 A 8=-9.08985e-11 A10= 1.59194e-12 A12=-4.38981e-15 Page 23 K = 0.00000e+00 A 4= 6.12566e-05 A 6= 1.17826e-07 A 8= 2.22470e-09 A10=-3.70114e-11 A12= 2.37590e-13 Various data Zoom ratio 2.00 Wide-angle Mid-range Telephoto Focal length 6.81 9.58 13.60 F-number 2.85 3.23 3.60 Half angle of view 58.57 57.09 57.85 Image height 11.15 14.80 21.64 Lens length 127.71 127.71 127.71 BF 30.73 40.08 49.42 d 4 6.34 6.31 2.10 d13 15.72 6.40 1.27 d20 2.33 3.71 3.67 d25 2.47 1.10 1.14 d28 30.73 40.08 49.42 Lens device group data Group starting plane focal length L1 1 -16.55 L2 5 -42.17 L3 14 26.64 L4 21 47.74 L5 26 -101.75

[0097] [Numerical Example 2] Unit: mm Surface Data Surface number rd nd νd 1 55.485 2.30 1.85150 40.8 2 19.371 17.05 3 -1103.546 1.30 1.90525 35.0 4 34.645 (variable) 5 37.524 0.90 1.89286 20.4 6 18.491 0.10 1.58946 30.6 7* 18.199 2.37 8 31.026 8.14 1.78880 28.4 9 -20.624 1.10 1.49700 81.7 10 16.423 5.40 11 -14.389 0.80 1.49700 81.7 12 18.091 3.89 1.61340 44.3 13 -39.413 (variable) 14 18.952 4.42 1.53172 48.8 15 -17.614 0.09 16 -17.868 0.70 1.88300 40.8 17 15.902 4.19 1.59270 35.3 18 -41.659 1.44 19 (Aperture) ∞ 1.27 20 34.703 4.01 1.49700 81.7 21 -25.217 (variable) 22 -26.388 0.80 1.88300 40.8 23 -78.439 0.10 1.53344 52.7 24* -49.028 0.15 25 31.715 4.97 1.49700 81.7 26 -18.785 (variable) 27 -53.258 0.75 1.88300 40.8 28 19.564 4.78 1.49700 81.7 29 -25.590 (variable) Image plane ∞ Aspheric data Side 7 K = 0.00000e+00 A 4=-9.88827e-06 A 6= 6.80002e-09 A 8=-9.44113e-12 A10= 1.04890e-12 A12=-2.43934e-15 Page 24 K = 0.00000e+00 A 4= 5.68392e-05 A 6= 1.09227e-07 A 8= 3.24013e-10 A10= 1.13582e-12 A12=-2.42531e-14 Various data Zoom ratio 1.97 Wide-angle Mid-range Telephoto Focal length 6.80 9.52 13.41 F-number 2.86 3.22 3.61 Half angle of view 58.61 57.24 58.16 Image height 11.15 14.80 21.60 Lens length 126.11 126.11 126.11 BF 30.90 39.23 47.55 d 4 4.47 5.13 1.29 d13 14.12 5.13 0.65 d21 4.03 3.69 2.74 d26 1.58 1.92 2.87 d29 30.90 39.23 47.55 Lens device group data Group starting plane focal length L1 1 -14.82 L2 5 -38.96 L3 14 27.05 L4 22 39.68 L5 27 -68.35

[0098] [Numerical Example 3] Unit: mm Surface Data Surface number rd nd νd 1 52.863 2.00 1.85150 40.8 2 19.811 16.64 3 268.068 1.30 2.00100 29.1 4 31.150 (variable) 5 159.698 4.99 1.95375 32.3 6 -30.207 1.20 1.49700 81.7 7 16.611 5.20 8 -17.533 0.80 1.49700 81.7 9 18.643 0.28 10 19.966 6.58 1.78880 28.4 11 -12.466 0.80 2.00100 29.1 12 -61.500 (variable) 13* 55.457 0.10 1.58946 30.6 14 97.068 3.52 1.56732 42.8 15 -14.576 0.05 16 -14.461 0.80 2.00100 29.1 17 22.989 3.89 1.59270 35.3 18 -25.500 0.15 19 52.181 4.70 1.63980 34.5 20 -16.612 0.30 21 (Aperture) ∞ (Variable) 22 -20.107 0.80 1.95375 32.3 23 -48.225 0.10 1.58946 30.6 24* -37.531 0.15 25 48.217 4.74 1.49700 81.7 26 -16.669 (variable) 27 -101.305 0.80 1.88300 40.8 28 18.672 3.74 1.49700 81.7 29 -30.910 (variable) Image plane ∞ Aspheric data Page 13 K = 0.00000e+00 A 4=-5.40095e-05 A 6=-1.58648e-07 A 8=-6.84435e-09 A10= 1.41530e-10 A12=-1.69897e-12 Page 24 K = 0.00000e+00 A 4= 3.89315e-05 A 6= 1.19235e-07 A 8=-4.99023e-10 A10= 1.75021e-11 A12=-1.12723e-13 Various data Zoom ratio 1.97 Wide-angle Mid-range Telephoto Focal length 6.82 9.56 13.42 F-number 2.83 3.21 3.60 Half angle of view 58.56 57.15 58.14 Image height 11.15 14.80 21.60 Lens length 123.73 123.73 123.73 BF 32.13 40.19 48.25 d 4 7.71 7.34 3.55 d12 13.02 5.32 1.05 d21 5.99 6.19 5.14 d26 1.25 1.05 2.10 d29 32.13 40.19 48.25 Lens device group data Group starting plane focal length L1 1 -14.97 L2 5 -42.81 L3 13 23.42 L4 22 53.48 L5 27 -82.35

[0099] [Numerical Example 4] Unit: mm Surface Data Surface number rd nd νd 1 60.163 2.60 1.83481 42.7 2 21.063 12.33 3 109.832 1.50 1.59522 67.7 4 17.672 (variable) 5 150.019 4.20 1.72047 34.7 6 -51.359 1.58 7 -37.627 0.90 1.89190 37.1 8 91.089 2.62 9 -17.827 0.85 1.49700 81.7 10 19.500 0.71 11 24.491 4.63 1.75520 27.5 12 -127.292 (variable) 13* 32.487 0.05 1.58946 30.6 14 24.928 6.44 1.53172 48.8 15 -10.792 0.85 2.00100 29.1 16 -49.566 0.15 17 260.837 3.61 1.59270 35.3 18 -19.964 0.06 19 -83.132 0.90 1.77250 49.6 20 12.974 5.93 1.59270 35.3 21 -21.635 0.87 22 (Aperture) ∞ (Variable) 23 20.807 4.87 1.49700 81.7 24 -19.178 0.15 25 -22.797 0.80 2.00100 29.1 26 -66.112 (variable) 27 -2019.764 0.80 1.88300 40.8 28 21.543 2.23 29 31.926 3.93 1.49700 81.7 30 -24.775 (variable) Image plane ∞ Aspheric data Page 13 K = 0.00000e+00 A 4= 7.64291e-06 A 6= 4.60507e-07 A 8=-1.46830e-08 A10= 3.93238e-10 A12=-3.23460e-12 Various data Zoom ratio 2.06 Wide-angle Mid-range Telephoto Focal length 7.22 10.80 14.86 F-number 2.88 3.61 4.12 Half angle of view 56.10 55.97 55.46 Image height 10.75 16.00 21.60 Lens total length 128.99 128.99 128.99 BF 32.52 42.88 49.78 d 4 9.19 8.61 5.93 d12 14.96 5.18 0.95 d22 7.59 6.65 3.60 d26 1.17 2.11 5.15 d30 32.52 42.88 49.78 Lens device group data Group starting plane focal length L1 1 -16.14 L2 5 -36.44 L3 13 35.25 L4 23 46.70 L5 27 -822.66

[0100] [Numerical Example 5] Unit: mm Surface Data Surface number rd nd νd 1 58.998 2.50 1.76385 48.5 2 15.716 16.74 3 -118.695 1.40 1.59282 68.6 4 37.945 (variable) 5 52.243 3.96 1.66565 35.6 6 -30.668 0.59 7 -22.962 1.00 1.90043 37.4 8 23.854 (variable) 9 23.518 3.91 1.66565 35.6 10 -20.591 1.00 1.49700 81.7 11 22.024 (variable) 12 18.264 1.00 1.88300 40.8 13 11.917 4.60 1.68430 26.8 14 -39.891 0.15 15 -32.692 1.00 2.05090 26.9 16 17.207 5.02 1.59410 60.5 17 -18.631 0.50 18 (Aperture) ∞ (Variable) 19 20.545 2.96 1.53775 74.7 20 -202.410 (variable) 21 -60.820 1.28 1.77250 49.6 22* 52.786 0.52 23 80.866 3.72 1.49700 81.7 24 -23.726 0.15 25 -31.425 1.31 1.88300 40.8 26 52.500 3.91 1.49700 81.7 27 -17.095 (variable) Image plane ∞ Aspheric data Page 22 K = 0.00000e+00 A 4= 2.64230e-05 A 6=-4.03358e-09 A 8= 7.40566e-10 A10=-2.79295e-11 A12= 2.33887e-13 Various data Zoom ratio 2.03 Wide-angle Mid-range Telephoto Focal length 7.24 10.93 14.69 F-number 4.10 4.10 4.10 Half angle of view 56.05 55.67 55.77 Image height 10.75 16.00 21.60 Lens total length 127.38 127.38 127.38 BF 32.32 43.68 51.25 d 4 13.34 9.39 4.19 d 8 5.91 6.34 6.60 d11 11.80 3.96 1.33 d18 3.21 3.73 3.00 d20 3.58 3.06 3.79 d27 32.32 43.68 51.25 Lens device group data Group starting plane focal length L1 1 -14.79 L2 5 -25.40 L3 9 64.83 L4 12 41.50 L5 19 34.85 L6 21 -442.01

[0101] [Numerical Example 6] Unit: mm Surface Data Surface number rd nd νd 1 58.154 2.50 1.76385 48.5 2 15.775 16.08 3 -425.603 1.40 1.59282 68.6 4 37.744 (variable) 5 248.610 5.62 1.77047 29.7 6 -19.550 1.00 1.95906 17.5 7 -38.557 (variable) 8 -22.637 1.00 1.91354 36.8 9 28.532 3.85 10 28.132 5.18 1.77047 29.7 11 -21.134 1.00 1.43875 94.7 12 22.654 (variable) 13 24.356 6.32 1.68430 26.8 14 -13.488 1.00 2.00100 29.1 15 28.481 4.91 1.51823 58.9 16 -15.181 0.40 17 (Aperture) ∞ (Variable) 18 22.580 3.05 1.49700 81.7 19 -104.450 (variable) 20 -34.188 1.28 1.76450 49.1 21* 87.503 2.04 22 32.469 4.26 1.49700 81.7 23 -18.234 0.15 24 -176.617 1.31 1.88300 40.8 25 19.236 3.68 1.49700 81.7 26 -61.995 (variable) Image plane ∞ Aspheric data Page 21 K = 0.00000e+00 A 4= 3.50880e-05 A 6= 1.70964e-08 A 8= 3.91104e-09 A10=-9.58126e-11 A12= 7.92141e-13 Various data Zoom ratio 2.06 Wide-angle Mid-range Telephoto Focal length 7.25 11.01 14.97 F-number 4.10 4.10 4.10 Half angle of view 56.00 55.46 55.27 Image height 10.75 16.00 21.60 Lens total length 131.41 131.41 131.41 BF 32.32 43.52 50.99 d 4 11.62 9.61 3.44 d 7 1.54 1.48 2.68 d12 13.54 4.41 1.90 d17 4.43 4.43 3.35 d19 1.92 1.92 3.00 d26 32.32 43.52 50.99 Lens device group data Group starting plane focal length L1 1 -16.36 L2 5 54.77 L3 8 -23.38 L4 13 42.94 L5 18 37.66 L6 20 -345.10

[0102] The various values ​​in each numerical example are summarized in Table 1 below.

[0103] [Table 1]

[0104] [Imaging device] Next, an imaging device to which the lens device L0 of this embodiment is applied will be described. Fig. 13 is a schematic diagram of an imaging device 10 of this embodiment. The imaging device 10 includes a camera body 13, a lens device 11 similar to any of the lens devices 11 of the above-described embodiments 1 to 6, and a light receiving element 12 that photoelectrically converts an optical image formed by the lens device 11.

[0105] The imaging device 10 of this embodiment has a lens device 11 that is small and has good optical characteristics, and therefore can obtain high-quality images.

[0106] It should be noted that an imaging element such as a CCD or CMOS sensor can be used as the light receiving element 12. In this case, various aberrations such as distortion and chromatic aberration of the image acquired by the light receiving element 12 can be electrically corrected to improve the image quality of the output image.

[0107] The lens device L0 of each of the above-described embodiments can be applied not only to the digital still camera shown in FIG. 13, but also to various optical devices such as silver halide film cameras, video cameras, and telescopes.

[0108] Although the preferred embodiments and examples of the present invention have been described above, the present invention is not limited to these embodiments and examples, and various combinations, modifications, and changes are possible within the scope of the gist of the present invention.

[0109] The disclosure of each embodiment also includes the following configurations.

[0110] (Configuration 1) an optical system including a first lens group having negative refractive power and a rear lens group having positive refractive power, arranged in this order from the object side to the image side; In the optical system, the distance between adjacent lens groups changes during zooming, the rear group includes one or more lens groups and an aperture stop; a focus group consisting of one or more lens groups among the lens groups included in the rear group, which moves in the optical axis direction during focusing; A lens apparatus that satisfies the condition ωw>85, where ωw (°) is a half angle of view when focused on infinity at the wide-angle end, the lens device includes a holding member that holds the focus group, and a drive member that moves the holding member in the optical axis direction; A lens device characterized in that the driving member and the aperture stop overlap in a direction perpendicular to the optical axis.

[0111] (Configuration 2) The lens device according to configuration 1, wherein the following conditional expression is satisfied, where fL1 is the focal length of the first lens group and fw is the focal length of the lens device at the wide-angle end. -3.0 <fL1 / fw<-1.7

[0112] (Configuration 3) the rear group includes a second lens group having negative refractive power, The lens device according to configuration 1 or 2, wherein the following conditional expression is satisfied, where fL2 is the focal length of the second lens group and fL1 is the focal length of the first lens group: -5.0<|fL2| / fL1<-1.1

[0113] (Configuration 4) The lens apparatus according to any one of configurations 1 to 3, wherein the following conditional expression is satisfied, where fG1 is the focal length of the lens G1 arranged closest to the object in the first lens group, and fL1 is the focal length of the first lens group: 1.4 <fG1 / fL1<3.0

[0114] (Configuration 5) The lens device according to any one of configurations 1 to 4, wherein the following conditional expression is satisfied, where fG1 is the focal length of the lens G1 arranged closest to the object in the first lens group, and fG2 is the focal length of the lens G2 arranged adjacent to the lens G1 on the image side: 0.40 <fG1 / fG2<1.60

[0115] (Configuration 6) 6. The lens device according to any one of configurations 1 to 5, wherein the following condition is satisfied, where fLF is the focal length of the focus group and fw is the focal length of the lens device at the wide-angle end. 3.5 <fLF / fw<15.0

[0116] (Configuration 7) 7. The lens apparatus according to any one of configurations 1 to 6, wherein the following condition is satisfied, where fLF is the focal length of the focus group and fL1 is the focal length of the first lens group: -4.1 <fLF / fL1<-1.8

[0117] (Configuration 8) 5. The lens device according to any one of configurations 1 to 7, characterized in that the following conditional expression is satisfied, where fL1 is the focal length of the first lens group and fLRw is the focal length of the rear group at the wide-angle end. -1.30 <fL1 / fLRw<-0.55

[0118] (Configuration 9) A lens device according to any one of configurations 1 to 8, wherein the following conditional expression is satisfied, where Skw is the back focus at the wide-angle end and fw is the focal length of the lens device at the wide-angle end. 2.0 <Skw / fw<6.0

[0119] (Configuration 10) The lens device according to any one of configurations 1 to 9, wherein the following conditional expression is satisfied, where DSPw is the distance on the optical axis from the aperture stop to the lens surface closest to the image in the entire system of the lens device at the wide-angle end, and Skw is the back focus at the wide-angle end: 0.40 <DSPw / Skw<1.00

[0120] (Configuration 11) 11. The lens device according to any one of configurations 1 to 10, wherein the refractive index at the d-line of the material of the lens G1 arranged closest to the object in the first lens group is ndG1, and the following conditional expression is satisfied: 1.65 <ndG1<2.20

[0121] (Configuration 12) the lens G1 located closest to the object in the first lens group is a negative lens having a meniscus shape with a convex surface facing the object side; 12. The lens device according to any one of configurations 1 to 11, wherein when the radius of curvature of the object-side lens surface of the lens G1 is R1 and the radius of curvature of the image-side lens surface of the lens G1 is R2, the following conditional expression is satisfied: 1.3<(R1+R2) / (R1-R2)<3.0

[0122] (Configuration 13) 13. A lens device according to any one of configurations 1 to 12, wherein the following conditional expression is satisfied, where Yta is the maximum image height at the telephoto end and Ywa is the maximum image height at the wide-angle end. 1.5 <Yta / Ywa<3.0

[0123] (Configuration 14) 14. The lens device according to any one of configurations 1 to 13, further comprising distortion correction data for correcting distortion.

[0124] (Configuration 15) 15. The lens device according to any one of configurations 1 to 14, wherein the first lens group has at least two negative lenses.

[0125] (Configuration 16) 16. The lens device according to any one of configurations 1 to 15, wherein the focus group is composed of two or less lenses.

[0126] (Configuration 17) 17. The lens device according to any one of configurations 1 to 16, wherein all of the lens surfaces of the lenses included in the first lens group are spherical.

[0127] (Configuration 18) The lens device according to any one of configurations 1 to 17, wherein the rear group is made up of three or more lens groups.

[0128] (Configuration 19) a first lens barrel for holding the first lens group; the lens G1 in the first lens group closest to the object has a meniscus shape with a convex surface facing the object side, The lens device according to any one of Configurations 1 to 18, wherein the vertex of the surface of the lens G1 on the object side is located closer to the object side than the first group barrel.

[0129] (Configuration 20) 20. The lens apparatus according to any one of configurations 1 to 19, wherein the focus group is disposed closer to the image side than the aperture stop.

[0130] (Configuration 21) The lens device described in any one of configurations 1 to 20, wherein the rear group consists of, arranged in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power.

[0131] (Configuration 22) The lens device according to any one of configurations 1 to 21, characterized in that the rear group comprises, arranged in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, a fifth lens group having positive refractive power, and a sixth lens group having negative refractive power.

[0132] (Configuration 23) The lens device according to any one of configurations 1 to 22, characterized in that the rear group comprises, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having negative refractive power, a fourth lens group having positive refractive power, a fifth lens group having positive refractive power, and a sixth lens group having negative refractive power.

[0133] (Configuration 24) 24. The lens device according to any one of configurations 1 to 23, wherein the driving member overlaps with the aperture stop in the optical axis direction.

[0134] (Configuration 25) a transmission member that transmits the driving force of the drive member to the holding member; The lens device according to any one of Structures 1 to 24, wherein the transmission member overlaps with the aperture stop in the optical axis direction.

[0135] (Configuration 26) a cylindrical member to which the driving member and the aperture stop are fixed, and a control board abutted against the cylindrical member; 26. The lens device according to any one of configurations 1 to 25, wherein the drive member overlaps with the control board in a direction perpendicular to the optical axis.

[0136] (Configuration 27) the control board has a notch, 27. The lens device according to any one of configurations 1 to 26, wherein the drive member overlaps with the notch in a direction perpendicular to the optical axis.

[0137] (Configuration 28) 28. The lens device according to any one of configurations 1 to 27, wherein the driving member is a stepping motor connected to a lead screw.

[0138] (Configuration 29) The lens device described in any one of configurations 1 to 28, further comprising a cylindrical member to which the drive member and the aperture stop are fixed, and the rear group comprises a filter holding member abutted against the cylindrical member.

[0139] (Configuration 30) a control board abutted against the cylindrical member; the filter holding member includes a drop-in filter; 30. The lens device according to any one of configurations 1 to 29, characterized in that the aperture stop, the holding member, the control board, and the filter holding member are arranged in this order from the object side to the image side.

[0140] (Configuration 31) 31. The lens device according to any one of configurations 1 to 30, wherein the lens device satisfies the condition ωw>92, where ωw (°) is a half angle of view when focused on infinity at the wide-angle end.

[0141] (Configuration 32) 33. An imaging device comprising: the lens device according to any one of configurations 1 to 32; and an imaging element that receives an image formed by the lens device. [Explanation of symbols]

[0142] L0 lens device L1 First lens group LR rear group LF Focus Group SP aperture stop 115 5-group lens barrel (holding member) 120 Rear group base barrel (barrel member) 122 driving member 123 Rack (transmission member)

Claims

1. an optical system including a first lens group having negative refractive power and a rear lens group having positive refractive power, arranged in this order from the object side to the image side; In the optical system, the distance between adjacent lens groups changes during zooming, the rear group includes one or more lens groups and an aperture stop; a focus group consisting of one or more lens groups among the lens groups included in the rear group, which moves in the optical axis direction during focusing; A lens apparatus that satisfies the condition ωw>85, where ωw (°) is a half angle of view when focused on infinity at the wide-angle end, the lens device includes a holding member that holds the focus group, and a drive member that moves the holding member in the optical axis direction; A lens device characterized in that the driving member and the aperture stop overlap in a direction perpendicular to the optical axis.

2. 2. The lens apparatus according to claim 1, wherein the following condition is satisfied, where fL1 is the focal length of the first lens group and fw is the focal length of the lens apparatus at the wide-angle end. -3.0<fL1 / fw<-1.7

3. the rear group includes a second lens group having negative refractive power, 2. The lens apparatus according to claim 1, wherein the following condition is satisfied, where fL2 is the focal length of the second lens group and fL1 is the focal length of the first lens group: -5.0<|fL2| / fL1<-1.1

4. 2. The lens apparatus according to claim 1, wherein the following conditional expression is satisfied, where fG1 is the focal length of the lens G1 arranged closest to the object in the first lens group, and fL1 is the focal length of the first lens group: 1.4<fG1 / fL1<3.0

5. 2. The lens apparatus according to claim 1, wherein the following conditional expression is satisfied: fG1 is the focal length of the lens G1 arranged closest to the object in the first lens group, and fG2 is the focal length of the lens G2 arranged adjacent to the lens G1 on the image side. 0.40<fG1 / fG2<1.60

6. 2. The lens apparatus according to claim 1, wherein the following condition is satisfied, where fLF is the focal length of the focus group and fw is the focal length of the lens apparatus at the wide-angle end. 3.5<fLF / fw<15.0

7. 2. The lens apparatus according to claim 1, wherein the following condition is satisfied, where fLF is the focal length of the focus group and fL1 is the focal length of the first lens group: -4.1<fLF / fL1<-1.8

8. 2. The lens apparatus according to claim 1, wherein the following condition is satisfied, where fL1 is the focal length of the first lens group and fLRw is the focal length of the rear group at the wide-angle end. -1.30<fL1 / fLRw<-0.55

9. 2. The lens device according to claim 1, wherein the following condition is satisfied, where Skw is a back focus at the wide-angle end and fw is a focal length of the lens device at the wide-angle end: 2.0<Skw / fw<6.0

10. 2. The lens apparatus according to claim 1, wherein the following conditional expression is satisfied, where DSPw is a distance on the optical axis from the aperture stop to the lens surface closest to the image in the entire system of the lens apparatus at the wide-angle end, and Skw is a back focus at the wide-angle end. 0.40<DSPw / Skw<1.00

11. 2. The lens apparatus according to claim 1, wherein the refractive index of the material of the lens G1 arranged closest to the object side in the first lens group is ndG1, and the following conditional expression is satisfied: 1.65<ndG1<2.20

12. The lens G1 located closest to the object side in the first lens group is a negative lens having a meniscus shape with a convex surface facing the object side, 2. The lens apparatus according to claim 1, wherein the following condition is satisfied, where R1 is the radius of curvature of the object-side lens surface of said lens G1, and R2 is the radius of curvature of the image-side lens surface of said lens G1. 1.3<(R1+R2) / (R1-R2)<3.0

13. 2. The lens device according to claim 1, wherein the following condition is satisfied, where Yta is the maximum image height at the telephoto end and Ywa is the maximum image height at the wide-angle end. 1.5<Yta / Ywa<3.0

14. 2. The lens device according to claim 1, further comprising distortion correction data for correcting distortion.

15. 2. The lens device according to claim 1, wherein the first lens group includes at least two negative lenses.

16. 2. The lens device according to claim 1, wherein the focus group comprises two or less lenses.

17. 2. The lens device according to claim 1, wherein all of the lens surfaces of the lenses included in the first lens group are spherical.

18. 2. The lens device according to claim 1, wherein the rear group comprises three or more lens groups.

19. a first lens barrel for holding the first lens group; the lens G1 closest to the object side in the first lens group has a meniscus shape with a convex surface facing the object side, 2. The lens apparatus according to claim 1, wherein the vertex of the surface of said lens G1 on the object side is located on the object side of said first group barrel.

20. 2. The lens apparatus according to claim 1, wherein the focus group is disposed closer to the image side than the aperture stop.

21. 2. The lens device according to claim 1, wherein the rear group comprises, arranged in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, and a fifth lens group having negative refractive power.

22. 2. The lens apparatus according to claim 1, wherein the rear group comprises, arranged in order from the object side to the image side, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, a fifth lens group having positive refractive power, and a sixth lens group having negative refractive power.

23. 2. The lens apparatus according to claim 1, wherein the rear group comprises, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having negative refractive power, a fourth lens group having positive refractive power, a fifth lens group having positive refractive power, and a sixth lens group having negative refractive power.

24. 2. The lens device according to claim 1, wherein the driving member overlaps with the aperture stop in the optical axis direction.

25. a transmission member that transmits the driving force of the drive member to the holding member; 25. The lens device according to claim 24, wherein the transmission member overlaps with the aperture stop in the optical axis direction.

26. a cylindrical member to which the driving member and the aperture stop are fixed, and a control board abutted against the cylindrical member; 26. The lens device according to claim 25, wherein the drive member overlaps with the control board in a direction perpendicular to the optical axis.

27. the control board has a notch, 27. The lens device according to claim 26, wherein the drive member overlaps with the notch in a direction perpendicular to the optical axis.

28. 2. The lens device according to claim 1, wherein the driving member is a stepping motor connected to a lead screw.

29. 25. The lens device according to claim 1, further comprising a barrel member to which the drive member and the aperture stop are fixed, and the rear group has a filter holding member abutted against the barrel member.

30. a control board abutted against the cylindrical member; the filter holding member includes a drop-in filter; 30. The lens device according to claim 29, wherein the aperture stop, the holding member, the control board, and the filter holding member are arranged in this order from the object side to the image side.

31. 2. The lens device according to claim 1, wherein the condition ωw>92 is satisfied, where ωw (°) is a half angle of view when focused at infinity at the wide-angle end.

32. 31. An imaging device comprising: the lens device according to claim 30; and an imaging element that receives an image formed by the lens device.

Images